Performance problem with Field or FieldArray during registration and unregistration fields

Are you submitting a bug report or a feature request?

Bug

What is the current behavior?

Check the sandbox below and click on Initialize button and then on Reset. Slow registration and unregistration bigger amount of fields(500 rows with 3 columns = 1500 fields). I have used subscription only to ‘value’ and ‘submitting’. I haven’t provided any validation yet but keep in mind that it will be also included for the subscription. I have tried also Field instead of FieldArray. In the sandbox, it is included as a comment.

What is the expected behavior?

Better performance.

Sandbox Link

https://codesandbox.io/s/youthful-morning-msnpk https://msnpk.csb.app/

What’s your environment?

"final-form": "^4.18.5",
"final-form-arrays": "^3.0.1",
"react": "16.8.6",
"react-dom": "16.8.6",
"react-scripts": "3.0.1",
"react-final-form": "^6.3.0",
"react-final-form-arrays": "^3.1.1"

Other information

<Form debug={console.log}> During initialization produce lot of records

I really love the final form. I have used redux-form, formik, react hook form and nothing is so powerful than your library. Just this performance makes me crazy. Thank you for help.

[nj314]

This issue is a major blocker for my current project. Is anyone able to suggest a workaround? My project has up to ~200 fields on the page, and the unmounting time is critical.

[joni3k]

Any updates on this?